0

0th

Percentile

Create a lightweight Shiny wrapper for the css-loaders created by Luke Hass <https://github.com/lukehaas/css-loaders>. Wrapping a Shiny output will automatically show a loader when the output is (re)calculating.

Add loader animations (spinners) to Shiny Outputs (e.g. plots, tables) in an automated fashion. Loading animations leverage on Shiny JS events and will show whilst the output value is not yet available or is 'out-of-date' (i.e. has been invalidated and the client hasn't received the new value). The spinners won't show if the output is not rendered (e.g. a validate or req is preventing it from being shown).

The advantages of using this package are:

• Automatic spinner showing / hiding. Just add one extra R function call (see below) and your output will have the spinner showing at just the right times
• Customizeable spinner colour (for each output or globally)
• Customizeable spinner size (for each output or globally)
• Choose from 8 different well-designed spinner types

The CSS animations are bundled from https://projects.lukehaas.me/css-loaders/, where you can see how they appear.

You can use it for any type of shiny output, by wrapping the UI element with the withSpinner tag:

# load the library

...

withSpinner(plotOutput("my_plot"))
# if you have %>% loaded, you can do plotOutput("my_plot") %>% withSpinner()

...


For outputs with uknown heights (e.g. tables), a 'proxy' container will be inserted, as the spinner cannot be centered with respect to a height that is uknown to the client (e.g. you might return a really large / small table, who knows?). By default the proxy container will be of height '400px', however if your output is expected to be substantially larger / smaller, you can adjust this with proxy.height option.

## Installation

The package is now available on CRAN (for outputs with variable heights, use the github version instead), however for the latest (and hopefully greatest!) version you can use the devtools package to install it from github directly:

devtools::install_github('andrewsali/shinycssloaders')


## Demo

To see how this works in action, you can check my example on shinyapps.io or run the example application from github directly:

shiny::runGitHub('andrewsali/shinycssloaders',subdir="example")


To see how the spinner works for outputs with undefined height, you can check out this example or run it from github directly:

shiny::runGitHub('andrewsali/shinycssloaders',subdir="example/table")


## Changing the spinner colour

You can specify a spinner colour for each output or set a variable globally.

### Locally for each output

Just add color attribute to withSpinner:

plotOutput("my_plot") %>% withSpinner(color="#0dc5c1")


### Globally

You can use options(spinner.color="#0dc5c1") to set the global colour.

### Background color

Spinner types 2-3 require you to specify a background color as well, which should match the background color of the container hosting the output. The other spinners work automatically without having to specify a background color.

## Changing the spinner size

The spinners scale in a relative fashion by specifying the size argument of withSpinner (default value is 1, so if you need to double the spinner for example, set size to 2). You can also set the size globally using options(spinner.size=my_size).